load_gen.v

以LVDS设计为例学习ISE中的时序分析以及低层布局器的使用方法 在底层布局器中对LVDS管脚进行约束的方法

//+FHDR---------------------------------------------------------------------
// Copyright (c) 2002, zte.
// zte Confidential Proprietary
// --------------------------------------------------------------------------
// FILE NAME :load_gen.v
// TYPE : module
// DEPARTMENT :
// AUTHOR : Xue Xiaogang 
// AUTHOR'S EMAIL : [e-mail]
// --------------------------------------------------------------------------
// Release history
// 
//   v00  2002-5-28 16:18  gen.
// --------------------------------------------------------------------------
// KEYWORDS : 
// --------------------------------------------------------------------------
// PURPOSE :   
//
// --------------------------------------------------------------------------
// PARAMETERS
// PARAM NAME            RANGE : DESCRIPTION        : DEFAULT : VA UNITS
//  
// --------------------------------------------------------------------------
// REUSE ISSUES
// reset_b_b Strategy :
// Clock Domains :
// Critical Timing :
// Test Features :
// Asynchronous I/F :
// Instantiations :
// Function and task used :
// Other : 
//-FHDR--------------------------------------------------------------------

module load_gen(
    clk,
    clk4x,
    loadrise,
    loadfall    
    );
    
input clk;
input clk4x;
output loadrise;
output loadfall;
            
VCC  U_vcc  ( .P( w_HI  )  );

//---------------------------------loadrise gen -------------------------------
wire lr0,lr1;
FDC load_FDC1 (.Q(lr0),      .C(clk),   .CLR(loadrise), .D(w_HI));
FDR load_FDR1 (.Q(lr1),      .C(clk4x), .R(loadrise),   .D(lr0));
FDR load_FDR2 (.Q(loadrise), .C(clk4x), .R(loadrise),   .D(lr1));

//---------------------------------loadfall gen--------------------------------
wire lf0,lf1,lf2;
FDC   load_FDC2 (.Q(lf0),      .C(clk),   .CLR(lf2),  .D(w_HI));
LDC_1 load_LDC_1(.Q(lf1),      .G(clk4x), .CLR(lf2),  .D(lf0));
FDR_1 load_FDR_1(.Q(lf2),      .C(clk4x), .R(lf2),    .D(lf1));
FD_1  load_FD_1 (.Q(loadfall), .C(clk4x),             .D(lf2));
         
endmodule

//-----------------------------------end 64 --------------------2002-5-28 16:43